
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
342 Driving and Operating
pickups. Trailer pin box extensions
and sliding fifth-wheel hitch
assemblies can help this condition.
There should be at least 15 cm (6 in)
of clearance between the top of the
pickup box and the bottom of the
trailer shelf that extends over
the box.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it
becomes separated from the hitch.
Instructions about safety chains
may be provided by the hitch
manufacturer or by the trailer
manufacturer. If the trailer being
towed weighs up to 2 271 kg
(5,000 lb) with a factory-installed
step bumper, safety chains may be
attached to the attaching points on
the bumper; otherwise, safety
chains should be attached to holes
on the trailer hitch platform. Always
leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 900 kg (2,000 lb) must be
equipped with its own brake system,
with brakes working on all axles.
Trailer braking equipment
conforming to Canadian Standards
Association (CSA) requirement
CAN3-D313, or its equivalent, is
recommended.
State and local regulations may also
require the trailer to have its own
braking system if loaded above a
certain threshold. These
requirements vary from state to
state.
Read and follow the instructions for
the trailer brakes so they are
installed, adjusted, and maintained
properly.
Do not tap into the vehicle's
hydraulic brake system.
Auxiliary Battery
The auxiliary battery provision can
be used to supply electrical power
to additional equipment that may be
added, such as a slide-in camper.If equipped, this relay will be on the
driver side of the vehicle, next to the
underhood electrical center.
Be sure to follow the proper
installation instructions included with
any electrical equipment that is
installed.
Caution
Leaving electrical equipment on
for extended periods will drain the
battery. Always turn off electrical
equipment when not in use and
do not use equipment that
exceeds the maximum amperage
rating of 30 amps for the auxiliary
battery provision.
Trailer Wiring Harness
The vehicle is equipped with one of
the following wiring harnesses for
towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, double cab, and crew
cab pickups have a seven-wire
trailer towing harness.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
350 Driving and Operating
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0144
. A device connected to the DLC
— such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 085 and Adding Equipment
to the Airbag-Equipped Vehicle
0 86.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.
Adding a Snow Plow or
Similar Equipment
Caution
Do not exceed 72 km/h (45 mph)
with a snow plow mounted to the
vehicle. The vehicle could
overheat and be damaged.
Before installing a snow plow on the
vehicle, follow these guidelines:
Caution
If the vehicle does not have the
snow plow prep package, RPO
VYU, adding a plow can damage
the vehicle, and the repairs would
not be covered by the vehicle
warranty. Unless the vehicle was
built to carry a snow plow, do not
add one to the vehicle. If the
vehicle has RPO VYU, then the
payload the vehicle can carry will
be reduced when a snow plow is
installed. The vehicle can be (Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 353
For example, adding a 318 kg
(700 lb) snow plow actually adds
more than 318 kg (700 lb) to the
front axle. Using the formula, if the
snow plow is 122 cm (4 ft) in front of
the front axle and the wheelbase is
305 cm (10 ft), then:W = 318 kg (700 lb)
A = 122 cm (4 ft)
W.B. = 305 cm (10 ft)
(W x (A + W.B.)/W.B. =
(318 x (122 + 305))/305 = 445 kg
(980 lb)
This means if the front axle reserve
capacity is more than 445 kg
(980 lb), the snow plow could be
added without exceeding the
front GAWR.
Heavier equipment can be added on
the front of the vehicle if less cargo
or fewer passengers are carried,
or by positioning cargo toward the
rear. This reduces the load on the
front. However, the front GAWR,
rear GAWR, and Gross Vehicle
Weight Rating (GVWR) must never
be exceeded.{Warning
On some vehicles that have
certain front mounted equipment,
such as a snow plow, it may be
possible to load the front axle to
the front Gross Axle Weight
Rating (GAWR) but not have
enough weight on the rear axle to
have proper braking performance.
If the brakes cannot work
properly, the vehice could crash.
Always follow the snow plow
manufacturer or installer's
recommendation for rear ballast
to ensure a proper front and rear
weight distribution ratio.
Maintaining a proper front and
rear weight distribution ratio is
necessary to provide proper
braking performance.
Total vehicle reserve capacity is the
difference between the GVWR and
the weight of the truck with full fuel
and passengers. It is the amount of
weight that can be added to the
vehicle before reaching the GVWR. Reserve capacity numbers are
intended as a guide when selecting
the amount of equipment or cargo
the truck can carry. If unsure of the
vehicle's front, rear, or total weight,
go to a weigh station and weigh the
vehicle. Your dealer can also help
with this.
The total vehicle reserve capacity
for the vehicle is in the lower right
corner of the Certification/Tire label
as shown previously.
See your dealer for additional
advice and information about using
a snow plow on the vehicle. Also,
see
Vehicle Load Limits 0265.
Emergency Roof Lamp
Provisions
Vehicles with the RPO VYU snow
plow prep package also have an
emergency roof lamp provision
package, RPO TRW. Wiring for the
emergency roof lamp is provided
above the overhead console. See
Auxiliary Roof-Mounted Lamp 0183
for switch location.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
364 Vehicle Care
1. Positive (+) Terminal. SeeJump Starting - North America
0435.
2. Battery - North America 0383.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System 0372.
4. Engine Air Cleaner/Filter 0371.
5. Automatic Transmission Dipstick (If Equipped). See
“How to Check Automatic
Transmission Fluid” under
Automatic Transmission Fluid
(6 Speed Transmission) 0368
or Automatic Transmission
Fluid (8 Speed Transmission)
0 371.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0364.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0364.
8. Engine Cooling Fan (Out of View). See Cooling System
0 372. 9. Remote Negative (–) Location.
See Jump Starting - North
America 0435.
10. Power Steering Fluid Reservoir.
SeePower Steering Fluid
(1500 Series) 0379 orPower
Steering Fluid (2500/3500
Series) 0379.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 380.
12. Brake Fluid Reservoir. See Brake Fluid 0381.
13. Auxiliary Battery (If Equipped). SeeBattery - North America
0 383.
14. Engine Compartment Fuse
Block 0393.
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax diesel supplement.
For an eAssist vehicle, see the
Silverado/Sierra supplement.Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
. Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
. Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0367.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
400 Vehicle Care
Number Usage20 –
22 HVAC/Auxiliary HVAC/Ignition
23 Instrument cluster/ Ignition sensing
diagnostic module/
Ignition
24 –
25 Data link connector/ Driver seat module
26 Passive entry/Passive start/HVAC
27 –
28 –
29 Park enable/ Electrically adjustable
pedals
30 SEO
31 Accessory/Run/Crank
32 Heated steering wheel
33 –
34 Instrument cluster
36 – Number Usage
37 –
38 4WD TREC
40 Left doors
41 Driver power seat
43 Left heated, cooled or ventilated seats (if
equipped)
44 Right heated, cooled or ventilated seats (if
equipped)
45 –
49 Retained accessory power
50 Run/CrankWheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. See Vehicle Load
Limits 0265.
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 439
6.6L
‐ To the negative (−) post on
the auxiliary battery, on the
vehicle with the dead battery.
11. Start the vehicle with the good battery and run the engine for a
while.
12. Try to start the vehicle that had the dead battery. If it will not
start after a few tries, it
probably needs service.
Caution
If the jumper cables are
connected or removed in the
wrong order, electrical shorting
may occur and damage the
vehicle. The repairs would not be
covered by the vehicle warranty.
Always connect and remove the
jumper cables in the correct order,
making sure that the cables do
not touch each other or other
metal.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
After starting the disabled vehicle
and removing the jumper cables,
allow it to idle for several minutes.
Towing the Vehicle
Caution
Incorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty.
Do not lash or hook to
suspension components. Use the
proper straps around the tires to
secure the vehicle.
Use only a flatbed tow truck for
towing a disabled vehicle. Never
use a sling type lift or damage will
occur. Use ramps to help reduce
approach angles if necessary.
A towed vehicle should have its
drive wheels off the ground.
Consult a professional towing
service if the disabled vehicle must
be towed.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Index 499
Antilock Brake System(ABS) (cont'd)
Warning Light . . . . . . . . . . . . . . . . . 146
Appearance Care
Exterior . . . . . . . . . . . . . . . . . . . . . . . 444
Interior . . . . . . . . . . . . . . . . . . . . . . . . 449
Apple CarPlay and Android Auto . . . . . . . . . . . . . . . . . . 237
Assistance Program,
Roadside . . . . . . . . . . . . . . . . . . . . . . 478
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . . . 308
Assistance Systems for
Parking and Backing . . . . . . . . . . 306
Audio Bluetooth . . . . . . . . . . . . . . . . . . . . . 215
Theft-Deterrent Feature . . . . . . . 189
Audio Players
CD . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Automatic Dimming Mirrors . . . . . . . . . . . . . . . . 49
Door Locks . . . . . . . . . . . . . . . . . . . . . 40
Forward Braking . . . . . . . . . . . . . . 310
Headlamp System . . . . . . . . . . . . 181
Transmission . . . . . . . . . . . . . . . . . 283
Transmission Fluid . . . . . . 368, 371
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . 286 Automatic Transmission (cont'd)
Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 387
Auxiliary
Roof Mounted Lamp . . . . . . . . . . 183
Auxiliary Jack . . . . . . . . . . . . . . . . . . . 214
Axle, Front . . . . . . . . . . . . . . . . . . . . . . 384
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . 385
B
Battery Load Management . . . . . . . . . . . . 186
Power Protection . . . . . . . . . . . . . 187
Voltage and ChargingMessages . . . . . . . . . . . . . . . . . . . 157
Battery - North America . . . . 383, 435
Blade Replacement, Wiper . . . . . 388
Blind Spot Mirrors . . . . . . . . . . . . . . . 49
Bluetooth Overview . . . . . . . . 222, 224, 228, 233
Bluetooth Audio . . . . . . . . . . . . . . . . 215
Brake
Pedal and AdjustableThrottle . . . . . . . . . . . . . . . . . . . . . . 273
System Warning Light . . . . . . . . 145
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 381 Antilock . . . . . . . . . . . . . . . . . . . . . . . 297
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 298 Brakes (cont'd)
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 381
Parking . . . . . . . . . . . . . . . . . . . . . . . 297
System Messages . . . . . . . . . . . . 158
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 254 Automatic Forward . . . . . . . . . . . 310
Break-In, New Vehicle . . . . . . . . . . 273
Bulb Replacement . . . . . . . . . . . . . . 392 Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 391
Halogen Bulbs . . . . . . . . . . . . . . . . 389
Headlamp Aiming . . . . . . . . . . . . . 389
Headlamps . . . . . . . . . . . . . . . . . . . 389
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . 390
Taillamps, Turn Signal, Stoplamps, and Back-up
Lamps . . . . . . . . . . . . . . . . . . . . . . 390
Buying New Tires . . . . . . . . . . . . . . . 418
C
Calibration . . . . . . . . . . . . . . . . . . . . . . 126
California Fuel Requirements . . . . . . . . . . . 316

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Index 503
General InformationService and Maintenance . . . . . 454
Towing . . . . . . . . . . . . . . . . . . . . . . . . 320
Vehicle Care . . . . . . . . . . . . . . . . . . 356
Glass Replacement . . . . . . . . . . . . . 389
Glove Box . . . . . . . . . . . . . . . . . . . . . . 119
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . . 478
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . 389
Hazard Warning Flashers . . . . . . . 182
Head Restraints . . . . . . . . . . . . . . . . . 56
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . 389
Automatic . . . . . . . . . . . . . . . . . . . . . 181
Bulb Replacement . . . . . . . . . . . . 389
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . 181
Flash-to-Pass . . . . . . . . . . . . . . . . . 181
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . 390
High-Beam On Light . . . . . . . . . . 151
High/Low Beam Changer . . . . . 180
Lamps On Reminder . . . . . . . . . 151
Heated
Steering Wheel . . . . . . . . . . . . . . . 125
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Heated Mirrors . . . . . . . . . . . . . . . . . . . 48
Heater
Engine Coolant . . . . . . . . . . . . . . . 278
Heating . . . . . . . . . . . . . . .243, 245, 246
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . . . 392
High-Beam On Light . . . . . . . . . . . . 151
High-Speed Operation . . . . . . . . . . 410
Hill and Mountain Roads . . . . . . . . 262
Hill Descent Control (HDC) . . . . . 301
Hill Descent Control Light . . . . . . . 147
Hill Start Assist (HSA) . . . . . . . . . . 298
Home Page . . . . . . . . . . . . . . . . 194, 196
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
How to Wear Safety Belts
Properly . . . . . . . . . . . . . . . . . . . . . . . . 66
HVAC . . . . . . . . . . . . . . . . .243, 245, 246
I
Idle System Fast . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Ignition Positions . . . . . . . . . . . . . . . 274
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . . . 388
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 45
Indicator
Vehicle Ahead . . . . . . . . . . . . . . . . 148 Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . . . 89
Infotainment . . . . . . . . . . . . . . . . . . . . 188
Infotainment System . . . . . . . . . . . . 487
Instrument Cluster . . . . . . . . . . . . . . 132
Instrument Panel Storage Area . . . . . . . . . . . . . . . . . .119
Interior Rearview Mirrors . . . . . . . . . 50
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jack Auxiliary . . . . . . . . . . . . . . . . . . . . . . 214
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . 435
K
Key and Lock Messages . . . . . . . . 160
Keyless EntryRemote (RKE) System . . . . . . . . . 36
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
L
Labeling, Tire Sidewall . . . . . . . . . . 402
Lamps Auxiliary RoofMounted Lamp . . . . . . . . . . . . . . 183
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 184
Daytime Running (DRL) . . . . . . 181
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 185